title: Endoscopic discectomy increases thoracic spine flexibility as effectively as open discectomy. A mechanical study in a porcine model.
abstract: METHODS
  Two surgical techniques for anterior discectomy were compared biomechanically. The surgical procedures were performed in live, anesthetized, skeletally immature pigs. Spine flexibility was measured in vitro.
  
  
  OBJECTIVE
  To determine whether endoscopic techniques for discectomy are as effective as open procedures in increasing spine flexibility.
  
  
  BACKGROUND
  Although studies have verified that discectomy increases spine flexibility, no study has confirmed whether endoscopic techniques increase flexibility as effectively as standard thoracotomy, which is a substantially different procedure.
  
  
  METHODS
  The intervertebral disc between vertebrae T8 and T9 was resected from 30 live, anesthetized, adolescent pigs. In 15 pigs, the chest was opened via thoracotomy of the eighth rib, and the disc was excised. In the other 15 pigs, the disc was removed endoscopically. These motion segments and six intact controls were tested mechanically in side bending, flexion-extension, and axial rotation.
  
  
  RESULTS
  No statistically significant differences in flexibility were found between open and endoscopic groups in any loading direction. The statistical power to detect a 20% difference between surgical groups was > or = 95%.
  
  
  CONCLUSIONS
  Endoscopic and open techniques were equally effective in increasing spine flexibility. Because endoscopy may reduce surgical morbidity compared with open discectomy, these results support the use of endoscopy for the surgical correction of scoliosis before instrumentation.
authors.affiliation: Department of Orthopaedic Surgery, Children's Hospital Medical Center, Cincinnati, Ohio, USA.
authors.forename: E J
authors.initials: EJ
authors.lastname: Wall
authors.forename: D I
authors.initials: DI
authors.lastname: Bylski-Austrow
authors.forename: F S
authors.initials: FS
authors.lastname: Shelton
authors.forename: A H
authors.initials: AH
authors.lastname: Crawford
authors.forename: R J
authors.initials: RJ
authors.lastname: Kolata
authors.forename: D S
authors.initials: DS
authors.lastname: Baum
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D017586:Diskectomy / Q000379:methods*; D004724:Endoscopy; D018583:Pliability; D012600:Scoliosis / Q000601:surgery; D013514:Surgical Procedures, Operative; D013552:Swine; D013904:Thoracic Vertebrae / Q000601:surgery*